Hello, Suppose I have a drl file(s) that defines a rules package. I have loaded this into the rule base. At runtime however, my user may change the file(s) that defines the package. Do I need to call RuleBase.removePackage () before adding the newly modified drl code? Or will the rule base automatically update all the modified rules correctly? When I call removePackage, I get the following exception, but I'm not sure why... Warning: An error occurred compiling a semantic invoker. Errors should have been reported elsewhere. Exception in thread "main" java.lang.NullPointerException at org.drools.reteoo.ReteooBuilder.removeRule (Unknown Source) at org.drools.reteoo.ReteooRuleBase.removeRule(Unknown Source) at org.drools.common.AbstractRuleBase.removePackage(Unknown Source) at com.vsasset.rules.dynamic.RemovePkgTestCase.replaceRuleFile ( RemovePkgTestCase.java:58) at com.vsasset.rules.dynamic.RemovePkgTestCase.testLoad1AssertLoad2( RemovePkgTestCase.java:38) at com.vsasset.rules.dynamic.RemovePkgTestCase.main( RemovePkgTestCase.java:23) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke( NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke( DelegatingMethodAccessorImpl.java :25) at java.lang.reflect.Method.invoke(Method.java:585) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:90) Process finished with exit code 1 Thanks! Justine _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users